Hitachi, Ltd.

Other

Hitachi Device Engineering Co., Ltd.

Hirobumi Koshi

Hiroyuki Nitta

Satoru Tsunekawa

Mitsuru Goto

Hiroshi Watanabe

Atsuhiro Higa

Yukihide Ode

Hironobu Isami

Kazuyoshi Kawabe

Takeshi Maeda

Tsutomu Furuhashi

Makoto Kimura

Yoshihisa Ooishi

Masashi Nakamura

Akihiro Watanabe

A fast-write, high picture-quality LCD (Liquid Crystal Display) compatible with a high-resolution, large-sized liquid crystal panel. An output amplifier circuit of a liquid crystal driver circuit includes an amplifier configuration, which functions as an amplifier that amplifies the predetermined gray-scale voltage for output and as an amplifier that buffers the predetermined gray-scale voltage and outputs with no amplification, and a circuit for switching the above two types of amplifiers. In each horizontal period, a liquid crystal panel is driven by the amplified output for a predetermined period and by the buffered output for the rest of the period. A precharge control circuit is provided to check whether the gray-scale voltage is to be amplified depending upon display data.

Liquid crystal driver circuit and LCD having fast data write capability

A liquid crystal driving device for controlling a liquid crystal panel and a liquid crystal display apparatus. Reference voltages are generated in a data driver from input reference voltages, and reference voltages are selected in accordance with the settings of gray scale control registers thereby to control the gray scale voltages. The gray scale control registers can be set using a data bus for transferring the display data from a liquid crystal controller, and the gray scale control operation is performed by the liquid crystal controller in accordance with the image data

Liquid crystal driving device for controlling a liquid crystal panel and liquid crystal display apparatus

A fast-write, high picture-quality LCD (Liquid Crystal Display) compatible with a high-resolution, large-sized liquid crystal panel. An output amplifier circuit of a liquid crystal driver circuit includes an amplifier configuration, which functions as an amplifier that amplifies the predetermined gray-scale voltage for output and as an amplifier that buffers the predetermined gray-scale voltage and outputs with no amplification, and a circuit for switching the above two types of amplifiers. In each horizontal period, a liquid crystal panel is driven by the amplified output for a predetermined period and by the buffered output for the rest of the period. A pre-charge control circuit is provided to check whether the gray-scale voltage is to be amplified depending upon display data.

In a low power consumption data transmission circuit and method, and a liquid crystal display apparatus using the same, 24-bit display data is transmitted from a transceiver circuit to a receiver circuit through a transmission line so that the display data is displayed on a liquid crystal panel. The transceiver circuit has a holding circuit including an 8-stage shift register. The transceiver circuit outputs 24-bit data to the transmission line by use of first and second output circuits when data different from data held in the holding circuit is to be transmitted from the transmission line and outputs data indicative of a hold position in the holding circuit from the second output circuit when the same data as that held in the holding circuit is to be transmitted from the transmission line. When the data indicative of a hold position is transmitted and received, the receiver circuit decodes or restores the received hold position indicating data into 24-bit display data by use of data held in a holding circuit provided in the receiver circuit.

Low power consumption data transmission circuit and method, and liquid crystal display apparatus using the same

A liquid crystal display device includes a liquid crystal panel; a plurality of data drivers for applying, to the pixel elements, graduation voltages corresponding to the display data; a gate driver for selecting a pixel element to which a graduation voltage is to be applied; and a liquid crystal control circuit for controlling the data drivers on the basis of a transfer clock. Each data driver includes a reproducing circuit for reproducing the transfer clock input to the data driver such that the deviations between the duties of the display data and the transfer clock input to the data driver and the duties of the display data and the transfer clock output from the data driver become small, and for generating a latch clock, and a latch circuit for latching the display data input to the data driver.

Liquid crystal display device for displaying display data

In a data transfer circuit, a hold signal generating circuit generates and outputs a hold signal Hold when transmission data is equal to transmission data one cycle before, and sets a 3-state output buffer for transmission data to high-impedance state, while, in a data reception circuit, when the hold signal Hold is valid, a data reception circuit outputs the reception data held, thereby power consumption in a data bus which is terminated with a terminal resistor is reduced.

Data transfer device and liquid crystal display device

A liquid crystal display device includes a video signal line drive circuit which includes (1) a first drive voltage circuit including at least one first output circuit which outputs an LC driving voltage of positive polarity corresponding to display data, and at least one second output circuit which outputs an LC driving voltage of negative polarity corresponding to display data, the at least one first output circuit and the at least one second output circuit being arranged alternately in a first polarity order, (2) a second drive voltage circuit including at least one third output circuit which outputs an LC driving voltage of positive polarity corresponding to display data, and at least one fourth output circuit which outputs an LC driving voltage of negative polarity corresponding to the display data, the at least one third output circuit and the at least one fourth output circuit being arranged alternately in a second polarity order opposite to the first polarity order, (3) a first switching circuit which inputs display data to the first voltage drive circuit and the second voltage drive circuit in two different input orders which are alternated, and (4) a second switching circuit which supplies outputs from the first drive voltage circuit and the second drive voltage circuit to video signal lines of a liquid crystal display panel in two different output arrangements which are alternated in synchronism with the alternation of the two different input orders.

Liquid crystal display device wherein voltages having opposite

A method of driving the liquid crystal display device includes the steps of preparing a first drive voltage circuit formed by plural first output circuits having a latch circuit for latching display data and being connected to the latch circuit and outputting LC driving voltages of positive polarity and second output circuits having a latch circuit for latching display data and being connected to the latch circuit and outputting LC driving voltages of negative polarity arranged alternately, and a second drive voltage circuit formed by plural first output circuits having a latch circuit for latching display data and being connected to the latch circuit and outputting LC driving voltages of positive polarity and second output circuits having a latch circuit for latching display data and being connected to the latch circuit and outputting LC driving voltages of negative polarity arranged alternately in opposite polarity.

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Chosei, Japan

Hirobumi Koshi